Microscopic analysis of interface structure in InGaAs/InP MQW using Pendellösung oscillation around a satellite peak in high-resolution X-ray diffraction

Pendellösung oscillation around a satellite peak in an X-ray rocking curve has been used for investigating the interfacial structure in InGaAs/InP multiple quantum wells (MQW) on the atomic scale. The MQWs were grown by metalorganic vapor phase epitaxy with growth interruption during which the ambience was changed from AsH3 to PH3, and vice versa. It was found that, in AsH3 ambience before the InGaAs growth, the excess AsH3 flow time caused inter-layer compositional fluctuation due to three-dimensional growth in the interfacial structures. On the other hand, in PH3 ambience before the InP growth, it was found that the crystalline qualities of the interfacial structures were degraded owing to the As desorption from the grown InGaAs layers. These results show that the excellent sensitivity of Pendellösung oscillation around a satellite peak can be used to evaluate interfacial structures such as atomic-order transient layers in InGaAs/InP MQW.